const fs = require('fs');

const readtext = () => {
    return new Promise((resolve, reject) => {
        fs.readFile('./Demo5_4_3_1.txt','utf-8', (err, dataStr) => {
            if (err) reject(err)
            else resolve(dataStr);
        })
    })
}

async function main(){
    let text = await readtext();
    console.log(text);
}
main();
